• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.58-65
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• 1997

This research was carried out to evaluate the effect of process variables on mechanical properties of the wood fiber-thermoplastic fiber composites by turbulent air mixing method. The turbulent air mixer used in this experiment was specially designed in order to mix wood fiber and thermoplastic polypropylene or nylon 6 fiber, and was highly efficient in the mixing of relatively short plastic fiber and wood fiber in a short time without any trouble. The adequate hot - pressing temperature and time in our experimental condition were $190^{\circ}C$ and 9 minutes in 90% wood fiber - 10% polypropylene fiber composite and $220^{\circ}C$ and 9 minutes in 90% wood fiber 10% nylon 6 fiber composite. Both in the wood fiber - polypropylene fiber composite and wood fiber- nylon 6 fiber composite, the mechanical properties improved with the increase of density. Statistically, the density of composite appeared to function as the most significant factor in mechanical properties. Within the 5~15% composition ratios of polypropylene or nylon 6 fiber to wood fiber, the composition ratio showed no significant effect on the mechanical properties. Bending and tensile strength of composite, however, slightly increased with the increase of synthetic fiber content. The increase of mat moisture content showed no significant improvement of mechanical properties both in wood fiber - polypropylene fiber composite and wood fiber nylon 6 fiber composite. Wood fiber - nylon 6 fiber composite was superior in th mechanical strength to wood fiber-polypropylene fiber composite, which may be related to higher melt flow index of nylon 6 fiber(22g/10min) than of polypropylene fiber(4.3g/10min).

• 한국식품영양학회지
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• 제8권1호
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• pp.23-31
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• 1995

To provide the basic information of buckwheat insoluble dietary fiber (IDF) and efficient material for the buckwheat processed foodstuffs, buckwheat (Fagopyrum egculentum Moench) was germinated at 1$0^{\circ}C$ for 7 days and the contents and composition of the insoluble dietary fiber were examined at 24 hour intervals. The NDF and ADF contents in ungerminated seeds were 20.27%, 18.95% on dry weight basis, respectively. During the germination period, the NDF and ADF contents increased gradually. The cellulose, hemicellulose and lignin contents in ungerminated seeds were 11.10%, 1.32% and 7.85%, respectively. During the germination period, the cellulose and lignin contents increased. However, there was no significant change in the hemicellulose contents. The composition of cellulose and hemicellulose in the NDF decreased with germination time, whereas that of lignin increased. The IDF contents obtained by Prosky method were higher than the NDF contents obtained by Van Soest method. However, the IDF and NDF contents were closely correlated(r=0.9785, p<0.01). The cellulose(Xl), hemicellulose(X2), lignin(X3) and soluble dietary fiber (SDF) (BL) showed the significant regression equation(p<0.001) with the root length(Y). The multiple regression equation was Y = -12.1306 + 0.9213xl - 0.1615$\times$2 + 0.1071$\times$3 + 0.7397$\times$4 and R2(coefficient of determination) was 0.942.

• 한국지반신소재학회논문집
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• 제2권1호
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• pp.47-55
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• 2003

14가지 니들펀치 부직포 지오텍스타일의 섬유구성인자인 두께, 기공도, 섬유장 및 직경 등이 수평투수성에 미치는 영향을 평가하였으며, 두께변화, 수평투수도, 압축 하중 하에서의 수평투수성을 구성방정식에 의해 분석, 평가하였다. 그리고 섬유 패킹 밀도가 다른 라미나(laminar) 지오텍스타일 복합재료를 제조하여 라미나 구조가 수직투수성에 미치는 영향을 평가하였다. 수평투수도는 부직포 지오텍스타일의 두께가 증가할수록 커졌으며, 기공도와 섬유직경이 커질수록 수평투수계수는 증가하였다. 수직응력이 증가할수록 기공도의 영향은 감소하였으며, 섬유장이 길수록 수평투수계수는 약간 크게 나타났다. 구성섬유의 직경이 클수록 수평 투수계수는 커지며, 직경의 비슷할수록 유사한 투수계수를 나타내었다. 라미나 지오텍스타일의 수직 투수성은 내부 경계면에서의 손실 수두에 영향을 받으며, 경계면에서 투수로의 연결형상은 bell mouth형이거나 부드러운 유입관 형태로 평가 되었다.

• 한국지역사회생활과학회지
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• 제15권3호
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• pp.57-61
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• 2004

Many studies have presented results about the antioxidative and antimicrobial activities of Dandelions (Taraxacum officinale). There has yet to be a study which makes comparisons of nutrients based on the parts of the Dandelion. To identify the nutrient composition by part of dandelion, nutrient contents were analyzed. Dandelions were taken from Songpa-gu in Seoul and the nutrient composition of the flower, leaf and root were measured. The nutrient content of each part was analysed by using the method developed by the Association of Official Analytical Chemists (AOAC). The proximate components(moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamins of the dandelion were analysed. The nutrient composition of the dandelions showed many significant differences among the parts when the differences were determined by using Duncan's multiple range test. The leaf contains more protein, ash, Ca, K, Mg, Zn, vitamin A, B$_1$, B$_2$, and C than the other parts. The root has much more fiber, carbohydrate, P and Fe content. The results demonstrate that dandelions could be used as a food source supplement for fiber, Ca, Fe and vitamin B$_2$ which are common nutritional deficiencies in Korea. It is recommended that more research for other bio-functional factors besides nutrients composition is needed to enhance the utilization of the dandelion.

• 한국산학기술학회논문지
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• 제3권2호
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• pp.89-93
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• 2002

PbO 함유 다성분계유리 및 파이버를 제조하였으며, PbO함유 유리는 이중도가니법(double crucible methodo에 의한 높은 개구수를 갖는(high-numerical aperture : N.A.) 광파이버(optical fiber) 제조에 적합하였다. 본 실험에 있어서는 SiO₂, PbO를 주성분으로 하고 K₂O, Na₂O, B₂O₃, A1₂O₃등의 산화물을 적량 배합하였으며, 또한 double crucible method에 의해 제조된 파이버의 광학적, 기계적 및 구조적 특성을 관찰하였다.

• 한국자원식물학회지
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• 제21권3호
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• pp.222-225
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• 2008

Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.

• 대한기계학회논문집A
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• 제29권6호
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• pp.876-888
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• 2005

Tensile properties and fracture toughness of monolithic aluminum, fiber reinforced plastics and glass fiber/aluminum hybrid laminates under tensile loads have been investigated using plain coupon and single-edge-notched specimens. Elastic modulus and ultimate tensile strength of GFMLs showed different characteristic behaviors according to the Al kind, fiber orientation and composition ratio. Fracture, toughness of A-GFML-UD which was determined by the evaluation of $K_{IC}$ and $G_{IC}$ based on critical load was similar to that of GFRP-UD and was much higher than monolithic Al. Therefore, A-GFML-UD presented superior fracture toughness as well as prominent damage tolerance in comparison to its constituent Al. By separating Al sheet from GFMLs after the test, optical microscope observation of fracture zone of GFRP layer in the vicinity of crack tip revealed that crack advance of GFMLs depended on the orientation of fiber layer as well as Al/fiber composition ratio.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.425-426
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• 2007

• Journal of the Korean Wood Science and Technology
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• 제15권2호
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• pp.99-104
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• 1987

Fiber mats were made at various density levels, using fibers from papermill sludge, ricestraw and various mixtures of the two. The paper mill sludges were collected from Moorim Papermill Co, and Jeonjoo Papermill Co. They were soaked in the liquid sulfur compounds, sulfur-tall oil and sulfurpolyester compounds, and made into fiber-reinforced, sulfur-based composition board. Under optimum conditions of fiber mat preparation and saturation with molten sulfur and modified sulfur, the Young's moduls of the manufactured tiber-reinforced composition board are superior to those of conventional wood-based composition boards. For example, the moduli of elasticity of the composition board made from papermill sludge, with a density of 0.40gm/$cm^3$, were greater than 1,400,000psi as compared 800,000psi for high density hardboard(1.28gm/$cm^3$). The modulus of rupture of the best reinforced composition board manufactured was over 9000psi, comparable to 6000psi of high density hardboard. The proposed Bryant and Lee's theory, "Modified Rule of Mixtures" can be applicable to the nonoriented and short fibrous composition board, when it was modified from "Rule of Mixtures" established by Paul an Jones, and supplemented by Smith and Cox's theory, In the Bryant and Lee's theory of $E_c=\frac{1}{3}aE_fV_f+bE_mV_m$, the constants "a" and "b" for the composition boards made from papermill sludge and the mixtures of ricestraw and the sludge were identified to be in the ranges of 3.29~3.54 and -2.47~-2.80 respectively.

• 한국결정성장학회지
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• 제23권4호
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• pp.180-188
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• 2013

삼척도계지역의 탄광에서 석탄채굴시에 부산물로 발생되는 사암계 석탄폐석을 원료로 사용하여 E-glass fiber 조성의 유리를 제조하였다. 본 연구에서는 카본함량이 비교적 적은 실리카-알루미나질의 사암계 석탄폐석을 사용하였으며, 폐석의 투입량을 0~35 %까지 변화시켰다. 서로 다른 석탄폐석 투입량을 갖는 배치원료를 $1550^{\circ}C$에서 2시간 용융하여 E-glass조성을 갖는 투명하고 맑은 유리가 얻어졌고, 81~84 %의 높은 가시광투과율, $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$의 열팽창계수, 851~$860^{\circ}C$의 연화점을 나타내었다. 유리섬유 시편은 $1150^{\circ}C$에서 섬유인상장치를 통해 얻어졌고, 복합재료의 보강용 유리섬유로서 내화학성 시험과 기계적 특성평가를 위한 인장강도를 측정하였다. 그 결과 석탄폐석을 사용한 E-glass fiber의 특성이 석탄폐석을 사용하지 않은 보통 E-glass 섬유에 비해 충분히 양호한 특성을 나타내어 E-glass 섬유용 원료로서 석탄폐석의 활용가능성을 확인할 수 있었다.